scholarly journals Theoretical modeling of two-photon absorption of benzoxazoles exhibiting excited state proton transfer

2018 ◽  
Vol 26 (2) ◽  
pp. 55-58
Author(s):  
Y. Syetov
Keyword(s):  
Absorption Spectra ◽  
Cross Section ◽  
Cross Sections ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Photon Absorption ◽  
Linear Absorption ◽  
Functional Theory ◽  
Two Photon Absorption ◽  
Two Photon

Two-photon absorption spectra of 2-(2'-hydroxyphenyl)benzoxazole, 2,5-bis(2-benzoxazolyl)phenol and 2,5-bis(2-benzoxazolyl)hydroquinone are modeled by time-dependent density functional theory calculations. In contrast to the linear absorption, where the transitions to the two lowest excited states are leading, the two-photon absorption cross sections are significant for the transitions to higher states which are weak in one-photon absorption spectra. The 2,5-bis(2-benzoxazolyl)phenol and 2,5-bis(2-benzoxazolyl)hydroquinone demonstrate the maximum cross section of about ten times larger than that of 2-(2'-hydroxyphenyl)benzoxazole. The largest value of the cross section is calculated for 2,5-bis(2-benzoxazolyl)hydroquinone to be about 1500 units of Goeppert-Mayer for excitation at 600 nm.

Bisporphyrin connected by tetrathiafulvalene

2009 ◽  
Vol 13 (01) ◽  
pp. 114-121 ◽  
Author(s):  
Kazuya Ogawa ◽  
Yasunori Nagatsuka
Keyword(s):  
Cross Section ◽  
Density Functional ◽  
Polar Solvent ◽  
Soret Band ◽  
Oxidation Potential ◽  
Time Dependent ◽  
Photon Absorption ◽  
Functional Theory ◽  
Two Photon Absorption ◽  
Two Photon

A new porphyrintetrathiafulvalene composite, where two porphyrins are bridged by te trathiafulvalene (TTF) using acetylene bonds was synthesized. The Q-band of the monomeric porphyrin appears at 590 nm whereas that of the composite is red-shifted to 620 nm and intensified. The Soret band is also red-shifted from 427 nm to 435 nm and much broadened, indicating the expansion of π-conjugation over the porphyrin and tetrathiafulvalene units. The HOMOs and LUMOs were calculated using time-dependent density functional theory. Voltammetric experiments revealed that the first oxidation potential of the TTF moiety in the composite was shifted by +155 mV compa red with TTF in the absence of composite. The effective two-photon absorption (2PA) cross section values were measured by using a nanosecond open aperture Z-scan method. The maximum effective 2PA cross section values were obtained at 760 nm, as 7300 GM in benzonitrile and 5900 GM in toluene. The values obtained in the polar solvent were 1.2 to 1.5 times larger than those in the nonpolar solvent.

Preparation and Photophysical Properties of All-trans Acceptor–π-Donor (Acceptor) Compounds Possessing Obvious Solvatochromic Effects

2017 ◽  
Vol 70 (9) ◽  
pp. 1048
Author(s):  
Yu-Lu Pan ◽  
Zhi-Bin Cai ◽  
Li Bai ◽  
Sheng-Li Li ◽  
Yu-Peng Tian
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Photophysical Properties ◽  
Emission Spectra ◽  
Photon Absorption ◽  
Linear Absorption ◽  
Functional Theory ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Donor Acceptor

A series of all-trans acceptor–π-donor (acceptor) compounds (BAQ, SFQ, BLQ, and XJQ) were conveniently synthesised and characterised by infrared, nuclear magnetic resonance, mass spectrometry, and elemental analysis. Their photophysical properties, including linear absorption, one-photon excited fluorescence, two-photon absorption, and two-photon excited fluorescence, were systematically investigated. All the compounds show obvious solvatochromic effects, such as significant bathochromic shifts of the emission spectra and larger Stokes shifts in more polar solvents. Under excitation from a femtosecond Ti : sapphire laser with a pulse width of 140 fs, they all exhibit strong two-photon excited fluorescence, and the two-photon absorption cross-sections in THF are 851 (BAQ), 216 (SFQ), 561 (BLQ), and 447 (XJQ) GM respectively. A combination of density functional theory (DFT) and time-dependent density functional theory (TDDFT) approaches was used to investigate the relationships between the structures and the photophysical properties of these compounds. The results show that they may have a potential application as polarity-sensitive two-photon fluorescent probes.

Calculations of two-photon absorption cross sections by means of density-functional theory

2003 ◽  
Vol 374 (5-6) ◽  
pp. 446-452 ◽  
Author(s):  
Paweł Sałek ◽  
Olav Vahtras ◽  
Jingdong Guo ◽  
Yi Luo ◽  
Trygve Helgaker ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Cross Sections ◽  
Density Functional ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Functional Theory ◽  
Two Photon Absorption ◽  
Two Photon

Theoretical studies on the one- and two-photon absorption of tetrabenzoporphyrins and phthalocyanines

2004 ◽  
Vol 82 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Xin Zhou ◽  
Ai-Min Ren ◽  
Ji-Kang Feng ◽  
Xiao-Juan Liu
Keyword(s):  
Dipole Moment ◽  
Cross Sections ◽  
Density Functional ◽  
Transition Dipole Moment ◽  
Photon Absorption ◽  
Transition Dipole ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Order Of Magnitude ◽  
The One

The one-photon absorption (OPA) properties of tetrabenzoporphyrins (TBPs) and phthalocyanines (Pcs) were studied using the semiempirical ZINDO method and time-dependent density functional theory (TDDFT), respectively. The compared results confirmed that the semiempirical ZINDO method was reasonably reliable when calculating the OPA of tetrabenzoporphyrins and phthalocyanines. On the basis of the OPA properties obtained from the ZINDO method, two-photon absorption (TPA) properties of two series of molecules were investigated, using ZINDO and sum-over-states (SOS) methods. The results showed that the TPA cross-sections of all molecules were in the range of 220.6 × 10–50 – 345.9 × 10–50 cm4·s·photon–1, which were in the same order of magnitude as the values reported in the literature. The relatively larger δ(ω) value for Pcs with respect to that for corresponding TBPs originates from larger intramolecular charge transfer, which can be characterized by the difference of dipole moment between S0 and S1 and the transition dipole moment between S1 and S5.Key words: two-photon absorption, ZINDO, sum-over-states, tetrabenzoporphyrin, phthalocyanines.

A small-molecule with a large two-photon absorption cross-section serves as a membrane-permeable ribonucleic acid (RNA) probe for live cell imaging

2018 ◽  
Vol 42 (17) ◽  
pp. 14325-14331 ◽  
Author(s):  
Ruiqing Feng ◽  
Longlong Li ◽  
Bing Li ◽  
Jinhui Li ◽  
Dan Peng ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Live Cell Imaging ◽  
Plasma Membranes ◽  
Cell Imaging ◽  
Photon Absorption ◽  
Absorption Cross ◽  
High Permeability ◽  
Two Photon Absorption ◽  
Two Photon

DMI could light up the RNA of the nucleus and the cytoplasm in living systems, which not only exhibits larger two-photon absorption cross-sections (981 GM), but also displays high-permeability to plasma membranes of vigorous cells.

Two-photon absorption spectra and cross-section measurements in liquids

Nature ◽  
1979 ◽  
Vol 280 (5720) ◽  
pp. 304-306 ◽  
Author(s):  
A. C. TAM ◽  
C. K. N. PATEL
Keyword(s):  
Absorption Spectra ◽  
Cross Section ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon
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